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Getting hum from my subwoofer

07-29-2018, 01:19 AM

I have a Dayton 450 watt plate amplifier powering a Dayton 12"dvc sub. I upgraded to a new receiver the other day and now I'm getting an intermittent hum from the sub. Tried lifting the ground, no luck. Took the plate out, don't see anything fried... It does go away after a bit and seem to function like normal but it comes back usually within 30 minutes or so. It's almost always present when the sub is first turned on and then might get quieter and trail off after a while. Think there's something up with the new receiver or that it's the plate amp or dvc going bad and it just happens to be a coincidence that it happened at the same time?

I presume your new receiver is not earthed? I don't know if this is equivalent to lifting ground on your plate amp but how about adding a ground to the receiver? I run an old pioneer sx-1280 and added aground. Havent had hum since.

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The new receiver is not earthed. However, the old one wasn't either and it was the same brand. (Sony). Also the subwoofer makes the noise without any signal cable attached. So if i have the RCA to the plate amp on the sub disconnected and just plug the power in to the sub and turn it on I get the hum...

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I had that problem with a Polk sub woofer, it turned out to be a blown capacitor. It was a loud hum which didn't vary with the volume setting of the speaker, which was strange. Replacing the cap fixed the problem.

Geoff

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i should also mention that it's more than a 60hz typical hum. i'm familiar with that one... this has a little mid-range to it and when there is audio playing through it the signal distorts in sub until it goes away, then it is clean again.

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Since the only thing that seems to have changed is the AVR, does the sub still make noise with the AVR off? Thinking it may be generating noise that the sub amp is picking up somehow? That it's not the 60 Hz noise is more rare of an issue. Change any cables since you swapped it out?
TomZ

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If the hum is persisting with only the power cord connected then it is most likely dirty power coming from your cable coax. You need one of these. Place it on your cable line as soon as it comes into your house. before any splitters or equipment. This should solve your problem, If not then there is something wrong with the amp itself. Its worth a 40 dollar filter to check to see if it's your cable before doing anything with the amp. Plus if the filter doesn't work you can always return it to Amazon.